The Child Support legislation allows (and even encourages) parents to reach agreement on the amount of child support to be paid. A child support agreement has to meet the requirements of the legislation and has to include matters that can be dealt with in a child support agreement. Once parents have made a child support agreement, either parent can apply to the Child Support Agency to have it accepted.

A child support agreement can be ended by a later child support agreement which provides for the liability under the earlier agreement to end. If an end date isn't specified the Child Support Agency will end the earlier agreement from the date of the later agreement.

Where a child support assessment existed immediately prior to the agreement and was modified by the agreement, the child support assessment continues when the agreement ends. The Agency will assess the liability in accordance with the relevant formula, including reinstating a change of assessment decision that existed prior to the agreement.

A parent can apply to a court to have a child support agreement set aside if they entered into the agreement because of fraud or undue influence or if their circumstances have substantially changed since the agreement was entered into. The parties to the application are the payer and payee in the case. The Child Support Agency is not a party to the appeal unless it decides to intervene in the court proceedings.

If a court sets aside the agreement it can make consequential orders to preserve or adjust the rights of the child or the parents.